1. Field of the Invention
The present invention relates to a pedestrian protection air bag system in which air bags which are adapted to cover front sides of left and right front pillars of a vehicle when they complete inflation are folded and accommodated, respectively, on left and right sides of a cowl below a hood panel of the vehicle near a rear end thereof.
2. Related Art
Some of conventional pedestrian protection air bag systems are configured such that air bags, which are folded, are accommodated, respectively, near left and right-hand sides of a cowl of a vehicle, so that when they have completed inflation, the air bags cover front sides of left and right front pillars of the vehicle (Refer to JP-A-2002-36986).
In those pedestrian protection air bag systems, a hood panel of the vehicle is configured such that a rear end side is raised to form a projection space between the cowl and a rear end of the hood panel for the air bags to project therethrough when they deploy and inflate while when in normal use a front end side is raised to open upwards by hinge mechanisms provided near left and right edges at the rear of the hood panel. The hinge mechanisms are each configured such that a bracket mounted at the rear of the hood panel is pivotally supported on a stay portion which extends upwards from a body side of the vehicle.
Then, in the pedestrian protection air bag systems, mechanisms for raising the rear end of the hood panel raise the stay portions themselves by means of actuators such as using solenoids to form the projection space between the cowl and the rear end of the hood panel for the air bags to project therethrough when the air bags deploy and inflate.
In addition, there is a pedestrian protection air bag system mounted which is not mounted on a cowl but on a hood panel and in which air bags are provided so as to cover front sides of front pillars, as well as upper surfaces of portions of the hood panel lying at a rear thereof (for example, JP-A-2006-44289). In this pedestrian protection air bag system, a panel side inflation portion of the air bag which is adapted to cover the upper surface side of the hood panel is internally roll folded in such a manner that a front end side is oriented downwards so that the panel side inflation portion is prevented from floating apart from the upper surface side of the hood panel when the air bag deploys and inflates, and following this, the panel side inflation portion so folded is then folded integrally with a pillar side inflation portion which is adapted to cover front sides of a windshield and a front pillar, whereby the air bag is so folded for accommodation in an accommodating location lying on a lower surface of the hood panel at a rear end thereof.
In the pedestrian protection air bag system which is configured such that the hinge mechanisms which are disposed at the end of the hood panel themselves are raised to raise the rear end of the hood panel so as to form the projection space for the air bags, however, moving portions of the actuators need to travel a distance equal to an open distance of the projection space formed at the rear of the hood panel, and the actuators need, in turn, to be enlarged, which is undesirable in consideration of the application of the relevant air bag system to a vehicle where space is limited.
In addition, in order for the air bags to cover the front sides of the front pillars in a stable fashion when they complete inflation, the air bags are desirably disposed, respectively, near locations lying directly below the front pillars (at the front thereof). However, the hinge mechanisms of the hood panel are provided in the locations lying directly below the front pillars, and hence, it is difficult to dispose cases which accommodate therein the folded airbags in the locations lying directly below the front pillars. Furthermore, the air bags tend to easily interfere with (contact) the hinge mechanisms part-way to deployment and inflation, and when considering their purpose of covering the front sides of the front pillars in the stable fashion, there have still been room for improvement.
In addition, in the conventional pedestrian protection air bag systems, while irregular portions are formed on a lower side of the hood panel for guiding the air bags when they deploy, the air bags come to interfere with these irregular portions when they deploy and inflate, whereby a quick deployment of the air bags is interrupted.
Furthermore, in the conventional pedestrian protection air bag systems, the air bags are made to positively interfere with the hinge mechanisms so as to use the locations of the hinge mechanisms to prevent the lateral deviation thereof, and portions of the air bags where their positions are restricted come to lie on lower sides of the front pillars and to constitute part of proximal portions which are spaced away from projection ends of the air bags. In this configuration, when contact conditions of the air bags with the hinge mechanisms differ from as designed, resulting positions of the projection ends of the air bags tend to easily deviate largely from the designed positions, and therefore, on the contrary to the designed manner, there is caused a fear that a smooth deployment of the air bags cannot be secured in a stable fashion.
Further, in the pedestrian protection air bag system which is mounted on the cowl, when the air bags are made to cover the upper surface of the hood panel, since the hood panel is raised to form the projection space for the air bags, there will easily be caused a fear that the portions of the air bags which are originally designed to cover the upper surface side of the hood panel deploy and inflate on the lower surface side of the hood panel.
In addition, in the pedestrian protection air bag system which is mounted on the cowl, when the air bags are made to cover the front pillars, the portions of the air bags which are originally designed to cover the front pillars desirably deploy and inflate smoothly and stably so as to cover the front pillars while suppressing the interference (contact) with the hinge mechanisms of the hood panel. Furthermore, even though the front pillars are covered, there still remain corner portions where the rear end of the hood panel intersects the lateral side edges thereof directly below the front pillars, and hence, the air bags desirably deploy and inflate smoothly and quickly so as to cover the upper surface side of the hood panel including the corner portions.